They have been doing more than patching for bugs. They have been expanding on the game, reviewing game features, introducing new balances etc

In the last two updates, it is clear they have reviewed the rules for encounters as you now meet a whole new composition of road encounters. So much my character no longer rides but runs.

They have reworked the NPC AI who are now much better at using terrain and setting up ambushes (it still happens though you see them hiding before they are hid), followers are better at following, dragons might have been added one or two new behaviours. They have consistently worked on the economy and how holding activity should act on another.

The legendary feature adds the possibility to steep up the difficulty of the game drastically. Character level 40, I made his two handed ability legendary and suddenly everything was made very hard to kill. As you can redistribute perks, you can choose to avoid those that gives such an edge to the character.

I had a big fight against an elder dragon as it probably must have been. I lost my companion on the way (forgot to untick the wait here command) and spotted a troup of atmer elves escorting a prisoner. Just as the character prepared to assault them, a dragon swooped in. The prisoner was fast down and it took five minutes to kill the dragon. One atmer died in the meantime, the two others were one blow away from their death. Dragon's attack were more distributed all over its opponents and no longer focused on the dragonborn.